Tibaldi A.

Department of Electronics and Telecommunications, Politecnico di Torino, Turin, Italy; IEIIT-CNR, Turin, Italy


D01–Challenges in multiphysics modeling of dual-band HgCdTe infrared detectors

Vallone M., Goano M., Tibaldi A., Hanna S., Eich D., Sieck A., Figgemeier F., Ghione G., Bertazzi F.

We present three-dimensional simulations of HgCdTe-based focal plane arrays (FPAs) with two-color and dual-band sequential infrared pixels having realistic truncated-pyramid shape taking into account the presence of compositionally-graded transition layers. Simulations emphasize the importance of a full-wave approach to the electromagnetic problem, and the evaluations of the optical and diffusive contribution to inter-pixel crosstalk indicate […]

D05–Enhanced dynamic properties of Ge-on-Si mode-evolution waveguide photodetectors

Palmieri A., Shafiee A., Alasio M. G. C., Tibaldi A., Ghione G., Bertazzi F., Goano M., Vallone M.

This work discusses coupled three-dimensional electromagnetic and electrical simulations of a Ge-on-Si waveguide photodetector where light is fed through a lateral waveguide. The numerical results show that this coupling solution leads to more uniform photon and carrier  distributions along the Ge absorber compared to a conventional butt-coupled detector, allowing a broader electrooptical bandwidth for high […]

LD03–Modulation response of VCSELs: a physics-based simulation approach

Gullino A., Tibaldi A., Bertazzi F., Goano M., Daubenschuz M., Michalzik R., Debernardi P.

A preliminary study of the dynamic behaviour of a GaAs/AlGaAs 850 nm VCSEL is presented, with the focus on the small-signal analysis and in particular on the optical amplitude modulation response. Simulations are performed with our in-house quantum-corrected one-dimensional drift-diffusion code D1ANA, updated to perform the AC analysis. The -3 dB cutoff frequency of the […]

LD04–Modeling Tunnel Junctions for VCSELs: A Self-Consistent NEGF-DD Approach

Tibaldi A., Gullino A., Gonzalez Montoya J., Alasio M. G. C., Larsson A., Debernardi P., Goano M., Vallone M., Ghione G., Bellotti E., Bertazzi F.

In this work we investigate carrier transport in tunnel junctions for vertical-cavity surface-emitting lasers by a novel self-consistent simulation framework for semiconductor quantum devices. Based on a Poisson-drift-diffusion foundation, in this approach quantum features are described through a nonequilibrium Green’s function formalism. The simulator is validated through a comparison with experimental results.

LD05–Optical Design Issues in Electrically Pumped Tunable Liquid-Crystal VCSELs

Simaz A., Tibaldi A., Boisnard B., Camps T., Bertazzi F., Goano M., Reig B., Doucet J. B., Bardinal V., Debernardi P.

In this work we investigate a tunable 850nm laser based on a hybrid combination of a liquid crystal micro-cell and a half GaAs VCSEL. The target application is optical coherence tomography. The inherent tolerances of the hybrid technology, the presence of metals in the cavity and the need for a pure extraordinary mode lasing make […]

LD07–Thermal Characterization of the Birefringence of Nematic Liquid Crystals for the Design of Widely-tunable LC-VCSELs

Simaz A., Boisnard B., Camps T., Doucet J. B., Reig B., Tibaldi A., Debernardi P., Bardinal V.

In this work, the thermo-optical properties of nematic liquid crystals are investigated through localized reflectance spectra measurements performed on a tunable LC-filter. The final aim is to insert such LC in the cavity of a tunable VCSEL device, in which local self-heating due to optical or electrical pumping must be taken into account. We demonstrate […]

NM05–Simulation of electro optic modulators based on plasmonic directional couplers

Ghomashi M., Tibaldi A., Bertazzi F., Vallone M., Goano M., Ghione G.

In this paper, a new concept and geometry are proposed for plasmonic modulators, whose operation is based on the coupling between two plasmonic slots. An electro-optic polymer is exploited as an active material, and the device can be implemented within a Silicon Photonics platform. The device operates at 1550nm wavelength, typical of data center or […]

PD04–Towards an efficient simulation framework for plasmonic organic hybrid E/O modulators

Tibaldi A., Ghomashi M., Bertazzi F., Vallone M., Goano M., Ghione G.

Due to the large computational resources required, with CPU times of the order of several days, full-wave optical simulators can be hardly exploited for the modeling and optimization of plasmonic organic hybrid electro/optic modulators. With the aim to drastically reduce such complexity, in this work we present a divide-et-impera strategy reducing the number of FDTD […]

SC01–Device level modeling of intermediate band quantum dot solar cells

Cappelluti F., Elsehrawy F., Tibaldi A.

Among many material candidates for next-generation solar cells, quantum dots offer unique opportunities. Aiming to maximally harness their nanoscale bandgap engineering, in this work we outline a multiscale, multiphysics modeling approach for the device level simulation of quantum dot solar cells. Examples of experimental validation are discussed, emphasizing the potential of light trapping techniques towards […]